Means for the controlled injection of a liquid additive



Nov. 20, 1962 J. D. BENNETT MEANSVFOR THE CONTROLLED INJECTION 0F' ALIQUID ADDITIVE Filed June l0, 1960 '.Illl |11 lnllllllllll I l llllvnllllxf 11.?

2 Sheets-Sheet l INVENTOR.

JOHN D. BENNETT ATTORNEYS Nov. 20, 19662 J. n. BENNETT MEANS FOR THECONTROLLED INJECTION OF A LIQUID ADDITIVE Filed June 10, 1960 2Sheets-Sheet 2 m Si? gi @I 4. M..

FIG. 3.

2 8 mmmm/m mmm INVENTOR.

United States liiig Patented Nov. 20, 1952 3,064,679 MEANS FR THECUNERRLED INJECTN F A LIQUED ADDHIVE .lohn D. Bennett. Richardson, Tex.,assigner to Sun @ii Company, Phiiadelphia, Pa., a corporatian of NewHersey Filed .lune 10, 1960. Ser. Nn. 35.172 15 Claims. (Cl. 137-5645)This invention relates to means for injecting a controlled amount ofliquid additive into a fluid line, and more particularly to such meansoperated by the pressure of such uid.

It is frequently desired to add certain chemical agents to fluids forthe purpose of inhibiting corrosion. for example, and this may beeffected by injecting the additive into a Huid line. Generally, it isdesirable to effect automatic continuous and uniform injection of theadditive in order to achieve the maximum beneficial effects.

Prior art methods of injection have generally employed pumps powered byauxiliary means or devices operable manually at intervals. Obviously theattainment of a continuous and uniform injection rate automatically,without the necessity for auxiliary operating means that are susceptibleto failure, affords decided advantages.

Accordingly, it is an object of the invention to provide means forautomatically injecting an additive continuously and uniformally into afluid line or other container.

it is a further object to effect the operation of such means byutilizing pressure in the line.

It is a further object to provide simple means for regulating the rateof injection of the additive.

Further objects and advantages will become apparent from the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIGURE l is an axial cross-section of the pump;

FIGURE 2 is a plan view of the pump;

FiGURE 3 is a vertical section of a Valve block, taken on line 3-3 ofFIGURE l, with the connecting tube and packing assembly removed; and

FIGURE 4 is a cross-section of a cylinder head taken on line 4-4 ofFIGURE 2.

While the invention is more broadly applicable, it is of majorcommercial value in introducing corrosion inhibitors into pipe linescontaining petroleum products, and for simplicity will be so described.

Referring to FIGURE l, the apparatus, which for purposes of descriptionwill be referred to hereafter as a pump, is intended to injectautomatically a small quantity of additive into a line 2 in whichliquid, or possibly a gas, is iiowing. The housing of the pump comprisesa pair of cylinders 3 and 5, preferably of stainless steel, which arefitted in annular grooves 6 and S, respectively, in a central valveblock it?. The left end of cylinder 3 is closed by a head 1li having anannular groove i6 into which the cylinder 3 is fitted. Likewise, theright end of cylinder is closed by a head i8 having an annular groove2li into which the cylinder 5 is fitted. Annular grooves 6, S, 16 and 29contain sealing gaskets formed, for example, of neoprene rubber. Thisassembly is held together by tie rods 21 passing through the valve block10 and bolted at the heads 14 and 1S.

A tube 22 is reciprocable through a central opening and packingassembly, indicated at 24, in the valve block 10. The packing assemblycomprises a resilient ring 26, of neoprene rubber for example,compressed between a pair of metal rings 28 and 30, these parts beingheld in place by a snap ring 32. A piston 34, having a resilient pistonring 36, is mounted on a plug 3S permanently fitted within the left endof tube 22. Piston 34 is held against the plug 38 and a sealing ring (orO-ring) 4d therein by a cotter pinned nut 2 and washer '44 on the shankof plug 3S. A second piston 46, having a piston ring 48, is mounted on aplug 50 permanently fitted within the right end of tube 22. Piston 46 isheld against plug 50 and a sealing ring 52 therein by a Cotter pinnednut 54 and washer 56 on the shank of plug Sli. Piston rings 36 and 4Spreferably are formed of a material such as neoprene rubber. It will benoted that a plurality of openings 58 are provided in the tube 22adjacent the left end thereof, the effect of these openings 58 beingmentioned hereafter. From the description thus far it will be evidentthat four separate chambers, of variable volume, are defined within thecylinders 3 and 5, and these chambers will be referred to hereafter asA, B, C and D.

A sight glass needle valve provided in block ttis generally indicated at60 and will be briey described, although it will be understood that suchvalves are conventional and commercially available. Referring to FIP-URE 3, a drilled passage 62 extends downwardly into block it),terminating at and connecting with a further passage 64 drilled from theleft side of block 10 and communicating with chamber B. A transparentglass or plastic tube 66 is seated in passage 62, being sealed byresilient rings 68, and is visible through a drilled through passage 67in block it). Closely fitted Within an enlarged bore 7l?, and sealed bya sealing ring 74, is a bushing 72 which is seated against the upper endof tube 66 and fixed in place by a snap ring 76. The stem 7S of theneedle valve has a tapered portion 77 adapted to mate with acorresponding tapered seat 79, in the bushing 72. A pointed extensionSli of stem 78 passes, with clearance, through the bushing 72 to effectthe formation of drops of liquid flowing through the valve, which dropsmay be visually observed through the transparent tube 66. Stem 78 isthreaded into bushing 72 and has a knob 82 by which the stem 78 may berotated to adjust the clearance between the tapered portion 77 and seat79. A fluid conduit 36' is tapped into block 10 and communicates with aspace S4 delined between the bushing 72 and bore 70. Through a port S7in bushing 72 liquid may flow from space 84 around the valve stem 73,forming drops which fall downwardly through passage 62 and past thewindow-like tube 66. It will be understood that by the adjustment ofknob 82 the rate of flow of liquid from conduit 86 through needle valve66 and into chamber B may be regulated.

Referring particularly to FIGURE 4, the other end of conduit 86 istapped into head 14 and communicates with chamber A through an internalpassage 8S. A ball check valve 90 permits the flow of liquid throughconduit 86 only in the direction from chamber A to needle valve 60.

A packed felt vent, of conventional nature, is provided in passages 92and 93, providing communication between chamber B and the exterior ofthe pump.

Referring to FIGURE 3, a transverse passage 94 is drilled into block l0from the side thereof and communicates with chamber B, and connects witha vertical passage 96 into which is tapped a iiuid conduit 96. Conduit93 is tapped at its other end into head 14 and communicates with chamberA through internal passages ifi@ and N2. A ball check valve 104 isprovided to permit the flow of liquid in conduit 9S only in thedirection from chamber B to chamber A.

A further valve, generally indicated at lit, is provided in a downwardlyextending and externally threaded neck 19S of valve block iti. Neck lhas three inwardly extending bores d, 112, and 1214 of progressivelydecreasing diameters, and a cylindrical member H5 positioned therein hasits upper end 114 closely fitted and seated within the upper and smallerbore il a liquid tight seal being provided by yan yO-ring. A space 116is defined between member 113 and bore 112, and also between member 113and a ring 118 seated and sealed within the upper end of bore 119.Member 113 is fitted within and sealed against the lower portion of ring11S at 120, and the outer diameters of member 113 and ring 118, with theexception in the latter case of shoulder 122, are less than the diameterof bore 11? to provide a space V124. The reduced lower end 12S of member1113 is received and sealed within a flanged nipple 126, and a snap ring139 retains the complete valve assembly within block 1b. A passage 132provides communication between space 12a and the interior of a fluidpipe ine when, as shown in FIGURE l, the pump is installed by screwingthe externally threaded neck 1113 into a fitting 133 in the line 2. Y

A fluid conduit 134. is tapped at one end into block 10 and at its otherend it is tapped into head 13 for communication with chamber D through adrilled passage 136. f

At the valve block 16, fluid conduit 134 communicatesV with space 124.Central bores 13S and 139, of relatively smaller and larger diametersrespectively, extend through the center of member 113, and a shortpiston 141i is urged upwardly in bore 139 by a coil spring 142 bottomedagainst nipple 126. Nipple 126 is so named because it has a long tubularneck 144 so that it will project well into the stream of lluid in pipeline 2, and has a central passage 146 communicating with the interior ofmember 113. A port 143 provides communication between space 116 and thespace lwithin lower bore 139 when piston 14() is in its extreme upperposition, which is the position shown in FIGURE 3. As shown particularlyin FGURE 1, a tube 150 extends from the upper portion of chamber C,curving around tube 22, and is permanently tted into block forcommunication with the space 116. Thus it will be seen that when piston140 is in its extreme upper position, which is the position shown inF'GURE 3, communication will be established between chamber C and theiluid line 2 through a path traceable as foliows: tube 150, space 116,port 148 bore 139 and bore 146. On the other hand, when piston 40 isforced downwardly-by liquid pressure acting from above-communicationwill be established between chamber C andthe space within upper bore 13Sthrough a path traceable as follows: tube 15%, space 116, port 148 andbore 133. As to chamber D, communication always is present between thischamber Vand the lluid line 2 through a path traceable as follows:passage 136, conduit 134, space 124, and passage 132. l

A passage 152 is drilled transversely into block 10, terminating at andconnecting with the bore Y13%. A fluid line 154 is tapped into passage152, and there are schematically illustrated a hand pump 156 and areservoir tank 15S for the liquid additive to be pumped into the luidline 2. Thus, when pump 156 is operated to pump liquid additive throughpassage 152 and bore 13S the pressure of the liquid willforce piston 146downwardly to a position below port 14S, thereby effecting the flow ofliquid additive through port 14S, space 116 and tube 15d into chamber C.'this matter of operation will be better understood from the followingdescription of the overall pump operation.

vChambers A and B are filled with what will be referred to hereafterV asVa control oil, and which preferably is an all weather medium viscositylubricating oil. At the Y time of assembly of the pump, and prior toputting it into operation, chambers A and B, as well as the interior oftube 22, are filled with control oil. This filling is effected with thepistons 34 and 46 and tube 22 at their extreme ber D. The pressure ofline fluid thereby existing in chamber D acts upon piston 46 in adirection toward the left (FIGURE l), tending to expel air, or liquidadditive left over from previous use, from chamber C through tube 159,space 116, port 143 and nipple 126 into line 2. (lt will be noted thatsince tubeV 159 opensY into chamber VC at the upper space thereof, airwill be expelled from chamber C in preference to left over liquidadditive.) Witr piston 46 at its extreme left hand position, the llingof chamber C with liquid additive is begun by the manual or motorizedoperation of a pump such as schematically illustrated herein at 156.Liquid additive is stored in reservoir 15S, and by the operation of pump156 it is pumped through conduit 154 into passage 152 and bore 138. Thetotal force of the pumped liquid additive acting on the upper side ofpiston 14u is greater than the combined force of the spring 142 and thefluid pressure acting upwardly on the underside of piston 1t-tl, thelatter pressure being that of the lluid in line 2. Therefore, piston isforced downwardly to a position below port 146', thereby permittingadditive to flow through port 148, space 116 and tube 150 into chamberC. The total force of the pumped liquid additive pressure in chamber Cacting to the right against piston 46 is greater than the total force ofthe line lluid pressure in chamber D acting to the left against piston46, and therefore piston i6 is driven to the right (FlGURE l),displacing line fluid from chamber D into line 2 via conduit 134, space124 and passage 132. lt will be understood that since the control oilpressure within tube 22 is substantially atmospheric, control oilpressure acting to the'right on plug Sti has little or no eec on theabove operation. In the course of movement of piston 46 to the right,corresponding movement of piston 34 displaces controloil from chamber Bto chamber A via conduit 98 and check valve 164.

The operation of pump 156 is continued until chamber C has been pumpedfull of liquid additive, i.e. when piston 46 has been moved to itsextreme right hand position as viewed in FIGURE l. As the operation ofpump 156 is discontinued, the combined force of spring 142 and the lineliuid pressure acting on the underside of piston 140 again is sufficientto move the same upwardly to the position shown in FIGURE 3, therebyre-establishing communication between chamber C and line 2 via tubeY150, space 116, port 148, bore 139 and nipple 126. At this point theadditive in chamber C and the line fluid in chamber D both are at theline iluid pressure. However, control oil at atmospheric pressure ratherthan additive at line pressure exists within tube 22, and therefore thepressure acting to the right against plug 50 is negligible. Theeffective working area, then, at the left of piston 46, excluding thecross-sectional area of tube 22, is less than the eifective working areaat the right of piston 46, and a differential area is provided whichcauses line fluid pressure in chamber D to move piston 46 to the left.Additive thereby is forced out of chamber C through tube 150 and isdischarged through nipple 126 into the line 2.

As piston 46 moves to the left, it drives piston 34 to the left also,forcing control oil out of chamber A through check valve 90 and needlevalve 60. However, the rate of movement of piston 34 to the left, andtherefore the rate of emptying of chamber C, is limited by the rate atwhich control oil can be displaced from chamber A and flow past needlevalve 60. Thus, by the setting of knob 32 the resistance to ow past thevalve stem extension 80 may be adjusted. The small amount of control oilthat is permitted to ow readily formsV into drops at the pointed end ofextension 80, and through the window-like tube 66 each drop may beobserved as it forms. The rate of flow of control oil from chamber Athrough conduit 86 and needle valve 60 is directly proportional to therate at which liquid additive is displaced from chamber B and injectedinto line 2, and therefore the frequency of the drops of control oilobserved serves as a direct indication of the additive injection rate.

Certain aspects of volume changes involved in operation of the pump willnow be expiained. Chambers A and B were lled with control oil whenpiston 34 was in the position at its left hand limit of movement asviewed in FIGURE 1. Therefore, the volume of control oil initiallyprovided approximately corresponds to the volume of cylinder 3, plus asmall volume of control oil represented by the space within the portionof tube 22 then extending to the right of the left side of the block 10.However, assume next that piston 34 is in the position at its extremeright hand limit of movement. Now, the total volume available to containcontrol oil corresponds approximately to the volume of cylinder 3 and,in addition, the total volume within tube 22 along its entire length.Therefore, although when the piston 34 is at the left there is no roomfor air in chambers A and B, when piston 34 is at the right asubstantial air space is provided. During the filling of chamber C withadditive, when pistons 34 and 46 move to the right, the total volumeavailable for control oil increases and air is drawn through the feltvents 92, 93 into chamber B. Then, when the filling of chamber C iscompleted and pistons 34 and 46 again move to the left, a substantialair space will exist in chamber B into which the drops of control oilemanating from needle valve 60 may fall. It will be evident that if anair space does not exist within the vertical passage 62, this passagewill be filled with oil and the formation of drops of control oil thatare visible could not take place. As movement of pistons 34 and 46 tothe left continues, the volume of air in the upper portion of chamber Bwill progressively decrease, with air being expelled to the atmospherethrough felt vents 92, 93. By the time chamber C is completely emptiedof liquid additive and piston 34. reaches its extreme left handposition, chambers A and B both will be lled to the top with controloil. When chambers A and B are filled with control oil, as previouslydescribed, if the vertical passage 62 and conduit 86 also are filledwith control oil, then when the piston 34 reaches its extreme left handposition oil will begin to rise in passage 62 until it prevents theformation of drops of oil at the extension Si). This discontinuation ofthe free formation of drops of oil may serve as a sign that the chamberC is empty or almost empty and must be refilled with additive. Thisexpedient is not necessary, however, because, in practice, for a givenadjustment of the needle valve 66 the time which elapses during theemptying of the pump will be known through experience. In regard to theemptying period of the pump it should be borne in mind that in generalan inhibitor pump is intended to inject a very small quantity ofadditive in proportion to the line fiuid flow rate, and the rate ofinjection might be in terms of a certain number of drops of additive perminute. Thus the pump may take days or weeks to empty.

It will be understood that Various departures from the specificallydisclosed embodiments may be made without departing from the scope ofthe invention as defined by the following claims.

What is claimed is:

1. In combination with a pump having a movable pumping member andadapted for injecting an additive into a conduit or the like containinga fiuid under pressure, a closed cylinder, a piston reciprocable in saidcylinder dividing the same into separate chambers, means transmittingmovement of said pumping member to said piston for movement thereofrelative to said cylinder, a liquid within said cylinder, a bypass linefor the flow of said liquid between the chambers in said cylinder, andmeans indicating the occurrence and rate of flow in said bypass line,thereby to serve as an indication of pump operation.

2. Means for injecting an additive into a conduit or the like containinga fluid under pressure, comprising a closed cylindrical structure havinga wall member dividing the same into first and second cylinders, a firstpiston in one of said cylinders and a second piston in the other of saidcylinders, said pistons defining in each cylinder a pair of chambers, arod connecting said pistons and extending through a iiuid sealed openingin said wall member, a bypass line for the flow of liquid between thefirst and second chambers of said first cylinder, means for regulatingthe rate of flow through said line, means for indicating said rate offlow, means providing independent communication between said conduit andthe respective chambers of said second cylinder, the working area ofsaid second piston being less at the side thereof in said first chamberthan at the side in the second chamber of said second cylinder, andmeans for intermittently filling the last-mentioned first chamber withadditive.

3. Means for injecting an additive into a conduit or the like containinga fluid under pressure, comprising first and second closed cylinders,first and second pistons reciprocable respectively in said cylinders anddefining in each a pair of chambers, means providing independentcommunication between said conduit and the respective chambers of saidfirst cylinder, the working area at one side of said first piston beingless than at the other side, means for intermittently filling thechamber of said first cylinder at said first side with additive, meanstransmitting movement of said first piston to said second piston formovement of the latter relative to the second cylinder, a liquid withinsaid second cylinder, a bypass line for the ow of said liquid betweenthe chambers in said second cylinder, and means for indicating the rateof flow in said bypass line.

4. Means for injecting an additive into a conduit or the like containinga fluid under pressure, comprising first and second closed cylinders,first and second pistons reciprocable respectively in said cylinders anddefining in each a pair or" chambers, means providing independentcommunication between said conduit and the respective chambers of saidfirst cylinder, the working area at one side of said first piston beingless than at the other side, means for intermittently filling thechamber of said first cylinder at said first side with additive, meanstransmitting movement of said first piston to said second piston formovenient of the latter relative to the second cylinder, a liquid withinsaid second cylinder, a bypass line for the flow of said liquid betweenthe chambers in said second cylinder, and means for regulating the rateof fiow in said line, whereby the movement of said first piston iscontrolled.

5. Means for injecting an additive into a conduit or the like containinga fiuid under pressure, comprising first and second closed cylinders,first and second pistons reciprocable respectively in said cylinders anddefining with each a pair of chambers, means providing independentcommunication between said conduit and the respective chambers of saidfirst cylinder, the working area at one side of said first piston beingless than at the other side, means for intermittently filling thechamber of said first cylinder at said rst side with additive, meanstransmitting movement of said first piston to said second piston formovement of the latter relative to the second cylinder, a liquid withinsaid second cylinder, a bypass line for the dow of said liquid betweenthe chambers in said second cylinder, and a valve regulating the flow ofliquid in said line.

6. Means for injecting an additive into a conduit or the like containinga fluid under pressure, comprising first and second closed cylinders,first and second pistons reciprocable respectively in said cylinders anddefining with each a pair of chambers, means providing independentcommunication between said conduit and the respective chambers of saidfirst cylinder, the working area at one side of said first piston beingless than at the other side, means for intermittently filling thechamber of said first cylinder at said first side with additive, meanstransmitting movement of said first piston to said second piston formovement of the latter relative to the second cylinder, a liquid withinsaid second cylinder, a bypass line for the fiow or" said liquid betweenthe chambers in said second cylinder, and a restriction in said lineregulating the flow of liquid therein.

7. Means for injecting additive into a conduit or the like containing auid under pressure, comprising rst and second closed cylinders, iirstand second pistons reciprocable respectively in said cylinders anddeiining in each a pair of chambers, means providing independentcommunication between said conduit and the respective chambers of saidiirst cylinder, the working area at one side of said first piston beingless than at the other side, means for intermittently illingthe chamberof said iirst cylinder at said irst side with additive, means transmittow therein only from the tirstto the second of .the lastting movement ofsaid first piston to said second piston `liquid new therein only duringoperation of said iilling means.

S. Means for injecting an additive into a conduit or the like containinga duid under pressure, comprising a closed cylindrical structure havinga wall member dividing Y the same into irst and second cylinders, alirst piston in one Vot said cylinders and a second piston inthe otherof said cylinders, said pistons defining in each cylinder a pair ofchambers, a holiow connecting rod connecting said pistons and extendingthrough a uid sealed opening in said wall member, the interior of saidrod being sealed against communication with the interior of a firstchamber or" said second cylinder but having means providing suchcommunication with a first chamber of the irst cylinder, a bypass linefor the iiow of liquid between the iirst and second chambers of saidfirst cylinder, means for regulating the rate of ow through said line,means for indicating said rate of flow, means providing independentcommunication between said conduit and the respective chambers of saidsecond cylinder, the working area of said second piston being less atthe side thereof in said first chamber than at the side in the secondchamber of said second v cylinder, and means for intermittently idlingthe lastmentioned tirst chamber with additive.

9. Means according to claim 8, including a second bypass line for the owof liquid between the chambers of the rst cylinder, and a check valve insaid second line permitting said iiow therein only from the first to thesecond of the last-mentioned chambers.

l0. Means according to claim 8, including a check valve in said bypassline permitting said flow therein only from the Said second to the iirstof the chambers in said rst cylinder.

ll. Means according to claim 8, including a check valve in said bypassline permitting said ow therein only from the said second to the firstof the chambers in said irst cylinder, a second bypass line between thelast-mentioned chambers, and a check valve in said second linepermitting mentioned chambers.

.12. Means according to claim 8, kwherein said regula ing and indicatingmeans comprise a needle valve having a windowlike opening for thevisnaiobservation of liquid llovring through said needle valve. Y Y Y l13. Means for injecting an additive into -aconduit'or the likecontaining a fluid under pressure, comprising ,a closed cylinder, apiston reciprocable Vwithin said clynder and defining therewith a pairof chambers,the working area at one side of said piston being less thanthatV of the other side, means providing communication between theconduit and the chamber at said other side of the piston, means defininga passage for the injection of additive from the other chamber into theconduit, a pump for intermittently lling said other chamber, and meansresponsive to operation of said pump to close said passage. to owtherethrough.

14. Means for injecting an additive into a conduit or the likecontaining a uid under pressure, comprising a closed cylinder, apistonreciprocable within said cylinder and defining therewith a pairVof chambers, the working area at one side of said piston being lessthan that of the other side, means providing communication between theconduit and the chamber at said other side of the piston, a pump, atwo-way valve structure having a iirst position providing communicationzbetween the other chamber and the conduit and a second positioniuterruptingsaid communication and establishing communication betweensaid other chamber and said pump, said pump being adapted to iill saidother chamber with additive when the valve is in said second position,the valve being moved Vto saidrsecond position by the operation of saidpump. Y

l5. Means for injecting an Vadditive into aV conduit or the likecontaining a fluid under pressure, comprisinga closed cylinder, a pistonreciprocable within said cylinder and delining .therewith a pair ofchambers,lthe working area at one side of said piston being less thanVthat kof the other side, means providing communication between theconduit and the chamber at said other side of the piston,

a pump, a two-way valve structure having a rst position providingcommunication between the other chamber and the conduit and a secondposition interrupting said comjmunication and establishing communicationbetween said References Cited in the tile of this patent UNITED STATESPATENTS Hall Nov. 21, 1899 Shields 'Nov. 26, 1929,

